SncA is a member of the synuclein family of structurally related proteins that are prominently expressed in the central nervous system, which also includes beta- and gamma-synuclein. Synucleins are abundantly expressed in the brain and SncA and Snc-Beta inhibit phospholipase D2 selectively. SncA may serve to integrate presynaptic signaling and membrane trafficking. Aggregated SncA proteins form brain lesions that are hallmarks of neurodegenerative synucleinopathies. Defects in SncA play a role in the pathogenesis of Parkinson disease. SncA peptides are a major component of amyloid plaques in the brains of patients with Alzheimer disease. SncA shares 95% sequence homology with rat SncA. Rat SncA is specifically expressed in brain and is associated with synaptosomal membranes in neurons